# Thread: Newton's Law of Cooling

1. ## Newton's Law of Cooling

I was having not so much trouble with these questions, but rather I think there is something wrong with questions. The questions are exactly the same except for the time it takes for the object to 42 degrees. Now the questions tells you to find how long it takes for an object to cool to 42 when it has already been stated in both questions. I did all the working for both question and came up with 5 and 4 respectively.

Newton's Law of Cooling states that the rate of change with time of the temperature T of an object is directly proportional to the difference between the temperature T of an object and the temperature M of the surrounding medium. An object with temperature T˚=100˚ C is placed in a liquid held at 40˚ C. The object cools to 42˚ C in 5 minutes. How long will it take the object to cool to 42˚ C?

The answer they gave was 11.119.

Newton's Law of Cooling states that the rate of change with time of the temperature T of an object is directly proportional to the difference between the temperature T of an object and the temperature M of the surrounding medium. An object with temperature T˚=100˚ C is placed in a liquid held at 40˚ C. The object cools to 42˚ C in 4 minutes. How long will it take the object to cool to 42˚ C?

The answer they gave was 8.453.

Is it just me or are the questions wrong?